1. Field of the Invention
The present invention relates to systems and methods for processing geological data related to the shale layers penetrated during borehole drilling.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
When drilling wells in search of oil or gas, it is essential for oil exploration personnel to conduct a proper analysis of the geological formation to determine which drilling location is most likely to contain producible quantities of the desired hydrocarbon. This is especially important given the high initial and ongoing costs of drilling operations.
Exploratory wells are often drilled to determine if a particular horizon will be productive of minerals. When drilling such wells, a mud logger monitors and logs the drill cuttings and other parameters at regular intervals along the borehole depth. Often, the drilling bit is accompanied down the borehole by a tool that takes measurements of the geological structure of the hole as it is drilled. Such tools produce data that make up the electric logs or gamma-ray logs of the borehole, depending on the type of sensors present on the tool. It is from these electric logs or gamma-ray logs that attempts are made to map the strata and to determine the presence of hydrocarbon zones in the borehole and, hopefully, to indicate to the drilling company the location of the sought-after productive formations. However, such logs can be inaccurate and the tools can be costly and unreliable.
To improve the accuracy of analysis of the strata, it is possible to obtain core samples at specified depths within the borehole (called coring). When coring, a core bit is attached to the drill pipe and a column of rock is cut from the formation. This column of rock (the core) is then sent to a laboratory where it can be analyzed for the presence of oil and gas, and its other characteristics are determined. Once the core analysis is complete, it is possible to obtain a map of the geological structure of the borehole that is more accurate than electric or gamma-ray logging can produce. However, such a process, although highly accurate, is exceedingly costly and time consuming and is impractical to perform on a regular basis.
What is needed is a method for determining the presence of hydrocarbon layers within a borehole that is more accurate than traditional well logging methods, yet less costly and time consuming than coring. The present invention satisfies these needs and others, as demonstrated by the detailed discussion of the embodiments herein.